My recommendations on how to choose a phone and phone plan in the contiguous United States of America (USA).
- 1 choosing a phone service
- 2 choosing a phone network
- 3 choosing a phone company
- 4 choosing a phone plan
- 5 choosing a cellular phone type
- 6 choosing mobile antimalware
- 7 choosing a mobile operating system
- 8 choosing an Android device
- 9 when to replace an Android device
- 10 phone accessories
- 11 phone software
- 12 summary
- 13 references
choosing a phone service
For a typical consumer based in the contiguous USA, there are at least four major types of phones available: internet telephones, landline telephones, cellular telephones, and satellite telephones. Of these four types of phones, a cellular telephone (cellphone) is going to be the safest, most practical, and cheapest option for the typical user in the contiguous USA. Most critically, an internet telephone or landline telephone cannot be used outside the home or during any number of emergencies such as a car accident. The first and most important function of a telephone should be the ability to access emergency services whenever and wherever they are needed.
Cellular telephony is the most popular type of telephone service in the USA, so cellphones are well-established to have widespread support for both devices and service, including the ability to use them with hands-free vehicular speakerphones while driving, as required by law in many jurisdictions.        Remember to never text while driving. A satellite telephone has the widest possible geographic range (though there are locations where a cellular telephone will have service when a satellite telephone will not), but a satellite telephone will be much more expensive than a cellular telephone.
One advantage of a landline telephone connection is the ability to send and receive traditional faxes. However, it is still possible to send and receive electronic faxes from a cellular telephone connection and/or an internet connection.
choosing a phone network
There have traditionally been two major cellular telephone networking technologies in the USA: CDMA (Code Division Multiple Access) and GSM (Global System for Mobile Communications). Without going into all the technical details, you do not want to get a CDMA phone, and if possible you should always get a GSM phone on a GSM network. Some phone companies may only allow CDMA phones, and you should avoid using any phone company that does not allow GSM phones on their network. The majority of all cellular telephones in the world are GSM phones.   Popular phone companies in the USA that use CDMA include T-Mobile (Deutsche Telekom [German: German Telecom] Mobile, who purchased the Sprint Corporation in 2020), US Cellular (the Telephone and Data Systems United States Cellular Corporation), and Verizon Wireless.    Individual phones can be built to use either CDMA or GSM, so if you are buying a phone, you should ask to make sure that you are getting the GSM version.
choosing a phone company
Who is the best cellular telephone service provider depends on where you live. The best indicator of service quality can be determined by checking what phone companies own the cellular towers in your area. For some areas, cellular towers will be predominantly owned by just one or two companies, and then other phone companies will lease the use of the towers from whatever companies own the physical towers. Typically this makes no difference and you should still get good service even if your cellular phone service provider does not own the tower. However, who owns the local towers can make a difference when a tower is damaged (such as after a storm or during a disaster). This means more calls are being routed through fewer towers, and then the customers with the companies who own the working towers could get priority over the customers with the companies who do not own the local working towers. This could mean poorer phone quality and/or slower internet service, possibly when you need it the most. If you make the majority of your telephone calls from home, simply choosing whatever phone company owns the closest cellular telephone tower to your home address will likely give you the best quality of phone service for the majority of your calls.
- map of cellular towers in the USA:
In the linked map from ESRI ArcGIS (the Environmental Systems Research Institute Arc Geographic Information System), you will see that (as of August 2019) all fourteen cellular towers in Allegany County (Maryland) are owned by just two companies: either "USCOC OF CUMBERLAND, LLC" (the Telephone and Data Systems United States Cellular Corporation [US Cellular], with eight towers) or "NEW CINGULAR WIRELESS PCS, LLC" (the American Telephone and Telegraph Company [AT&T], with six towers).    Cellular tower ownership in neighboring Garrett County (Maryland) is more evenly divided between these two competitors, with five towers belonging to US Cellular and five towers belonging to AT&T (out of ten towers total in Garrett County, including two on the Allegany-Garrett border). However, US Cellular does not have as wide of a coverage network nationwide as AT&T does, so if you ever need to travel outside of the US Cellular coverage zone, you will be much better off with AT&T versus US Cellular.  
- AT&T cellular coverage map:
- US Cellular cellular coverage map:
I personally use AT&T (Prepaid). Before switching to AT&T though, I also tried using Verizon Wireless (from about 2006 to 2009) and US Cellular (from about 2009 to 2010), and had worse phone quality in Allegany County than I get now with AT&T. With the exception of some of the large mountainous state parks and forests in Garrett County (most notably New Germany State Park), I have never not been able to use my AT&T phone due to location, even when traveling. I have also always received excellent customer service from AT&T, both in person and over the telephone.
choosing a phone plan
You should always get a contractless or prepaid plan if possible. If you are signing up for a phone plan, and are asked for any personal information such as a driver's license number or Social Security Number, do not give it out! That type of information is typically only needed for phone contracts, which can lock you into paying higher rates than you need to, and affect your credit score. Additionally, if you are under a contract with the phone company, it can be very difficult to change your telephone provider if you ever need to. You should be able to be in charge of deciding what phone you want to use and what phone company you want to get service from, and have the freedom to change your mind any time you like, without being under the provisions of a legal contract that only benefits the phone company. Often the phone company will try to seduce you into signing a contract by offering you a "free" phone, but typically the higher rates you pay on a phone contract will end up costing you more than just buying your own phone (out of pocket) and then getting a contractless plan for it.
You also shouldn't have to live with caps on your service. Try to get an unlimited-everything plan if you can, such as AT&T Prepaid. With my AT&T Prepaid plan, I get unlimited calling, texting, and internet data so I never have to worry about being out of contact (in AT&T's coverage zones). Even from deep within the woods of the state parks of Allegany (Maryland), I can still livestream video and internet radio. For AT&T Prepaid, note that while total mobile internet data is unlimited, high-speed mobile bandwidth is not. You get a set amount of high-speed mobile data each month (which carries over to the next month if you don't use it), but if you hit the high-speed mobile data cap, the low-speed mobile bandwidth of 128 kilobaud (kilobits per second) should still be fast enough to check your email, browse the web, stream internet radio, and make internet audiocalls.   And if you still think 128 kilobits per second is slow, remember that the maximum bandwidth allowed by dial-up internet is 56 kilobaud.  However, AT&T Prepaid provides me with enough high-speed mobile data that I have never hit the high-speed mobile data cap. I get six gigabytes of high-speed mobile data per month (up to twelve gigabytes per month with rollover data), but I use much less than this since most of my smartphone use is on wifi. Remember to enable data-saving features on your mobile device such as only doing software installations and updates on wifi to save your high-speed mobile data for when you need it.
choosing a cellular phone type
There are two major types of cellular telephones: "feature" phones and "smart" phones. The main difference between these two is that a smartphone will have a computer operating system (OS) that will allow you to easily install third-party applications (apps), whereas a feature phone will typically be limited to just the features that come with the phone (feature phones are also sometimes called "dumbphones," in contrast to "smartphones"). I never really wanted a smartphone (I still prefer to use my phone as just a phone when possible), but AT&T offered me a discount on my monthly phone bill if I upgraded, and I figured at the time that the additional cost of a smartphone would eventually pay for itself (and then some) with a monthly discount on my prepaid phone service. However, I learned later that this isn't true since Google Android devices typically have to be replaced every three years or so.
The best reason to get a smartphone instead of a feature phone is for security. The limited operating system on a feature phone means that you cannot install antimalware onto the device, and this creates a major security risk. So if you want a secure cellular telephone, you need to get a smartphone that supports running active antimalware protection (i.e., a device running either Apple iPhone OS [iOS] or Google Android Linux OS). Note that mobile malware can also be spread by Short Message Service (SMS) text messages, making antimalware necessary on all devices that can send or receive text messages on the cellular network, not just those that can access the internet. 
choosing mobile antimalware
I cannot stress this enough, but every device connected to a wide area network (such as the Internet) should have active antimalware running on it at all times. If you have a phone without antimalware, you should perform a complete factory reset of the phone (including erasing and reformatting any attached storage cards), install active antimalware, and then change all of your passwords. Never enter a password on an unsecure device.
I use and recommend Netgear Armor Bitdefender Mobile Security for Android.  Bitdefender consistently gets the highest rankings for multi-device antimalware protection if you are using both Google Android and Microsoft Windows devices.  The Netgear Armor version is only available bundled with a Netgear Armor router. Otherwise, you can get Bitdefender Mobile Security bundled with Bitdefender Total Security, or just get the mobile app by itself.   Note that the Armor and non-Armor versions of Bitdefender Mobile Security for Android are incompatible with each other, so if you are upgrading to the Armor version, you need to uninstall the non-Armor version first.
If you want free antimalware for your mobile device (or can't afford Bitdefender), then I recommend Lookout Security, which is also recommended by AT&T.  I used Lookout Security before upgrading to Bitdefender Mobile Security.
Remember to never have installed more than one antimalware application at a time. If you are upgrading to Bitdefender, you must uninstall Lookout first.
- antimalware testing results for Google Android:
- Netgear Armor Bitdefender Total Security (includes Bitdefender Mobile Security):
- Bitdefender Total Security (includes Bitdefender Mobile Security):
- Bitdefender Mobile Security for Android:
- Bitdefender Mobile Security for iOS:
- Lookout Security:
choosing a mobile operating system
From a security perspective, you pretty much have only two choices for a mobile operating system: either Apple iPhone OS (iOS) or Google Android Linux OS. These are the only two mobile operating systems supported by Bitdefender Mobile Security, which I highly recommend that you get (preferably bundled with Netgear Armor). Most other mobile antimalware developers (including Lookout Security) will typically only support either Apple iOS or Google Android OS. Regarding whether Apple iOS or Google Android is better overall for security, Apple iOS devices technically do provide better security than Google Android or Android One devices do. However, Apple iPhone OS is a terrible environment to use if you want any decent smartphone features, especially for items such as data storage and music playback (you cannot natively use storage cards or wired headphones with Apple iPhones). If you actually want to use your smartphone for anything other than making phonecalls (and eventually you're gonna wanna), then you should get a Google Android device instead.
While there do still exist manufacturers of portable MP3 players, the market for portable MP3 players has largely been replaced by smartphones, which can also portably play MP3 files. If you trace the history of the Microsoft Zune MP3 player, the official replacement for the Zune after it was discontinued in 2011 was the Microsoft Windows Phone.  Windows Phone was itself discontinued in 2017, and Microsoft endorsed Google Android (over their competitor Apple) as the mobile platform of choice for both telephony and music playback for Windows users.   If you use Linux or Microsoft Windows as your desktop operating system, then an Android Linux mobile device will likely be more intercompatible with your desktop files and software than an Apple device will, though I have never used an Apple device. Something else to consider is that Apple iOS is a proprietary closed-source operating system whereas Google Android Linux is free and open-source.  Plus, Google Android Linux is the number-one most popular operating system in the world (for all devices, not just mobile devices), so there is a lot of support for it.
An incredibly poor decision on Apple's part is that Apple smartphones do not allow storage cards, so you are stuck with whatever storage capacity is provided by the phone's limited internal storage. Not being able to use internal storage cards on Apple smartphones is pretty much a deal-breaker, since you're likely going to need that extra storage capacity. By contrast, any modern Android phone will often allow over two terabytes (2 TB) of integrated storage capacity by adding a storage card. That's oodles of potential space for photos, music, movies, books, and a lot more. Two terabytes is about equivalent to the total number of books held in a research library for a major university, or about five million books.     Note that while two terabytes is the maximum capacity supported by SDXC (Secure Digital XC) flash storage cards (and phones with full SDXC support), trying to purchase an SDXC card with such a high capacity can be very expensive.  As of June 2020, Western Digital SanDisk only manufactures MicroSDXC cards with capacities of up to one terabyte (1 TB), but a one-terabyte card costs more per gigabyte than getting a lower-capacity MicroSDXC card. 
choosing an Android device
With regard to cybersecurity, there are two major problems with Google Android Linux. The first issue is that Android has a short support cycle of only three years. After three years from whenever a new version of Android is released, that version of Android is no longer supported. If the Android device cannot be upgraded to a newer version of Android before then, then the device has to be replaced, even if it is still in otherwise perfect working order. While there are technical challenges with continuing support beyond three years, this is a serious problem with the way Google manages Android, and a terrible waste of otherwise good phones by creating artificial obsolescence.  But if you want security, you should always make sure that your device is fully supported. You can refurbish an unsupported Android device as, for example, a point-and-shoot camera, an offline ebook reader, or an offline music player, but ideally it should never be used as a phone or connected to any kind of network (including the cellular telephone network, or any other mobile or wireless networks).
To make matters worse, the second problem is the way that Android devices are designed and built. Google Android Linux is a free open-source operating system. This means that anyone can freely download, modify, redistribute, and sell the Android Linux source code, more or less however they wish. This is usually a good thing. But what happens with phones is that third-party companies will modify the free open-source code with proprietary components to make it suit their particular needs and wants. So while the Android Linux operating system that is created by Google is open-source, the modified version of Linux distributed by most phone manufacturers in their phones is proprietary and no longer open-source. What this means then is that when Google releases a patch or update for their open-source code, the phone manufacturers who modified the code have to in turn modify the patches and updates to work with their particular proprietary versions of Android Linux. Unfortunately, this takes time and effort, and security updates can take weeks or even months to make it downstream from Google to the user when the updates have to be processed and modified by the phone manufacturer first. This makes most Android phones not directly manufactured by Google a lot less secure than they should be. This also means that when a new Android version is available, if you have a phone not manufactured by Google, you cannot easily upgrade it until the phone manufacturer has modified the source code from Google to work with the third-party proprietary modifications made for that particular model of phone. To make matters even worse, the phone manufacturers have little to no incentive to offer any software upgrades at all. They want you to buy a brand-new phone every single year, and not even wait the three years given by Google. It's also important to note that just because Google is releasing security updates for a supported version of Android, most phone manufacturers are under no legal obligation to pass those security updates to their customers. Phone manufacturers often release a new phone model every single year, and can choose to abandon providing security updates for a particular phone model at any time.
So what to do? Fortunately, Google is responsible enough to see some of the problems with this type of software ecosystem, and in particular the major security risks presented to the Android community by not getting security patches out quickly enough when the phone operating systems have been modified by third parties. Google's solution is Android One, which is the result of an agreement between Google and third-party phone manufacturers to make phones with Google-only software and no proprietary modifications to the open-source software that might impede the ability to apply security patches as quickly as Google can release them. In addition to always receiving the latest security updates before other phones get them, an Android One device is guaranteed to be provided a minimum of two version upgrades from whatever version of Android it is initially released with.  That means that you can keep your phone for up to five years instead of less than three years. Since all Android devices have a limited lifetime (unlike a Microsoft Windows Ten  device), the best deal is to get the cheapest possible Android One device you can, and then replace it every five years (or whenever it is getting close to its end of support). I would recommend to replace your Android device three months before it reaches its end of support.
I decided on the Lenovo Motorola Moto X4 Android One Edition as the cheapest phone for my needs. The Moto X4 was the very first Android One device to be released in the USA, in September 2017.  It currently runs on Android 9.0 Pie (after the Android One promise of two version upgrades from its initial release with Android 7.1 Nougat), and unless it gets an upgrade to Android 10, will become obsolete in August 2021 (three years from the release of Android 9).   The camera zoom and video autofocus are not very good, but you can use the money saved compared to getting a more expensive smartphone to get a dedicated point-and-shoot camera instead of trying to use your phone as a camera. And you can continue using the dedicated point-and-shoot camera for a much longer time than you can use the phone for. I do miss the advanced features on my first smartphone, a Samsung Galaxy Note Three (3), but I am comforted by the facts that I am saving money and am also much more secure now with an Android One device instead. I will say though that if you can afford a latest-model Samsung Galaxy Note, it really is the cream of the crop in terms of smartphone features available. However, in addition to having poorer security than Android One phones, Galaxy Note phones are not cost-effective, since they have to be replaced more often than Android One phones, and they also cost more for each replacement. You're literally throwing money away if the phone still works but you can no longer use it after it reaches its end of support, so the amortized cost per year of an Android One device is nearly always lower than a similarly-priced Android phone without Android One. If you want something with an active stylus, get a Microsoft Windows 10 tablet instead, which can be a lot cheaper, and will be supported forever (Microsoft Windows is now under a continuous development model, so that Windows 10 is currently planned to be supported forever by Microsoft). 
One specific hardware feature you should look for, is if you plan to use the phone for any navigational or astronomical functions (such as Celestron SkyPortal), you need a magnetic compass in the phone. A lot of smartphones do not include a magnetic compass in them, so you need to check for this specifically. The Global Positioning System (GPS) will only provide the phone's location; it cannot provide any directional information to determine in which direction the phone is facing without a magnetic compass.
For finding a specific smartphone to purchase, my recommendations are that it should be no more than one Android version out of date, have Android One, use GSM, have a screen resolution of 1920 × 1080 pixels or greater, have at least two gigabytes (2 GB) of random access memory (RAM), have at least thirty-two gigabytes (32 GB) of internal data storage, be capable of recording video with a resolution of 1920 × 1080 pixels or greater at a framerate of 60 frames per second or greater, and have a magnetic compass.  I have never had any problems with my Moto X4 Android One Edition running Android 9 with 3 GB of RAM and 32 GB of internal data storage. Sites like GSM Arena and Phone Arena have advanced phone finder tools that can help you to find the best device for your price range.
- GSM Arena Phone Finder:
- official list of Android One devices:
- Wikipedia list of Android One devices:
wikipedia:Android One#Products by year of announcement or release
when to replace an Android device
All Android devices should be replaced within three years of the release date for their Android version. As of April 2020, all devices running Android Seven (7) or earlier are no longer supported and should be replaced. Devices running Android Eight (8) need to be replaced by August 2020, devices running Android Nine (9) need to be replaced by August 2021, and devices running Android Ten (10) need to be replaced by September 2022. The most recent version of Android as of April 2020 is Android 10, which was released in September 2019.
- Android version release dates:
wikipedia:Android version history#Overview
If you can't afford to replace your Android smartphone but need to continue using it as a phone, then you should take every step possible to reduce the risk of using an unsupported device. This means that you should not use the phone for anything other than audio phonecalling and Short Message Service (SMS) via text only (no multimedia messaging and no internet access). Remove all applications, including factory-installed applications, except for your antimalware app. Never use the device to access the internet (other than for antimalware updates), and leave wifi, Bluetooth, and near-field communication (NFC) permanently disabled. Do not connect it to your computer or any other devices, including Bluetooth devices (pull your vehicle over if you need to make or receive a phonecall on the road). If possible, lock your phone into Safe Mode. For access to the Google Play Store in order to install antimalware software, you should create a second Google Account solely for use with your unsupported Android device (do not use your primary Google Account). For additional security, change your Google and Netgear (or Bitdefender) passwords every month (remember to always use long complex random passwords and never reuse passwords), and perform a factory reset on the device once a year (reinstalling your antimalware).
Unsupported Android devices can still be useful though if the proper precautions are made. I was able to refurbish my Samsung Galaxy Note 3 into a pretty good point-and-shoot camera (better than my Moto X4 camera). Having an old cameraphone around can be useful for certain types of photography that would be too dangerous to attempt with a newer or more expensive camera (such as unfiltered Solar imaging). After a factory reset, I removed all applications from the smartphone except for the factory-supplied offline-use-only apps (such as the camera app). It is permanently locked into Safe Mode, with wifi, Bluetooth, and NFC permanently disabled. It has never been connected to any networks since the factory reset, including the cellular telephone network (the phone does not have a subscriber identification module [SIM]). I use it for offline use only, by taking photos, and then uploading them to the computer by universal serial bus (USB). Remember that you cannot install any apps to the device without internet access (and it would not be safe to try). Another use for keeping old phones without phone service is that they should still be able to dial 911 for emergencies (in the USA), though I have never tested this (and you should not, unless there is an actual emergency).  Keeping an old cellphone in your vehicle could be life-saving to be able to reach emergency services if you accidentally leave your primary cellphone at home.
Every smartphone should have both a protective case and a screenprotector for it. Even if you are planning to replace it in three years, you want to protect your investment and not have to replace it sooner than that. I recommend a matte film antiglare screenprotector, which is what I use (from Supershieldz), which not only protects the screen but also makes it easier to read under bright light. Tempered-glass screenprotectors provide better protection than film screenprotectors, but you want a protector that has antiglare for the best visibility. Don't forget a car charger as well.
I recommend to not install any applications on your Android device unless they are absolutely necessary. A lot of businesses will pressure you into installing their apps. Don't fall for it. For many such apps, everything you can do from the app you can also do directly from the mobile web browser instead. If you are using Bitdefender Mobile Security (and I recommend that you do), your antimalware protection is going to work best by only entering or accessing sensitive information (such as passwords or bank accounts) through HTTPS (Hypertext Transfer Protocol Secure) on a Bitdefender-supported mobile web browser (such as Google Chrome, Mozilla Firefox, or Opera). This is exactly how you would enter or access the same information on your desktop computer, and it is much safer than using a third-party app. You do not need to install apps to do things you can already do from a web browser. If you are browsing on Chrome, and you see a pop-up asking you to install an app instead of using the website, don't do it. If you do think you need to install an app, first take some time to investigate who developed the application. Is the developer reputable? What other applications have they developed? Does the developer have a website and contact information available?
Remember also to never connect to untrusted wifi networks. In general, using your mobile data will be more secure than attempting to connect to an untrusted wifi network. Most public wifi access points should be considered as untrustworthy, especially if you don't know who set up the network, what kind of security they have, etcetera.
If you want to install just one app (after Bitdefender Mobile Security), I highly recommend the Celestron SkyPortal App for Android. This works best with a smartphone that has a magnetic compass, and will enable you to identify most celestial objects (with or without a telescope).
- check who owns the cellular telephone towers near your home
- do not use a cellular telephone service provider that does not allow GSM devices on their network
- compare nationwide cellular telephone coverage with local cellular telephone coverage, to make sure your phone still works the same when you are traveling
- do not get a phone contract; get a contractless or prepaid plan instead that allows you to bring your own device for activation on the cellular network
- get a GSM-compatible smartphone running either Apple iPhone OS or Google Android Linux OS (I recommend Android One)
- make sure your smartphone is running a supported operating system
- make sure your smartphone is running active antimalware (I recommend Bitdefender Mobile Security)
- if possible, do not connect to unsecure or public wireless networks
- only install apps from developers you trust
- only browse the web from secure browsers
- replace your smartphone when its operating system is close to reaching its end of support
wikipedia:mobile phones and driving safety
wikipedia:Restrictions on cell phone use while driving in the United States#Laws by state
wikipedia:comparison of mobile phone standards
wikipedia:List of CDMA2000 networks#Active_networks
wikipedia:United States Cellular Corporation
wikipedia:Dial-up Internet access#Performance
wikipedia:Microsoft Windows Phone
wikipedia:List of unusual units of measurement#Data volume
wikipedia:Library of Congress#Holdings
wikipedia:Android version history#Overview