House lawmakers said Tuesday that they will conduct a three-day series of hearings next week to look at how the Food and Drug Administration should regulate medical applications on smartphones and tablets. Lawmakers from the House Energy and Commerce committee will look specifically at how regulation affects patients, physicians and developers looking to capi­tal­ize on the growing field of mobile health and medical apps.

The hearings follow a letter the committee sent to the FDA earlier this month, in which lawmakers questioned whether the Patient Protection and Affordable Care Act could allow the FDA to define smartphones and tablets with health-related apps as “medical devices” — and levy new taxes on developers and smartphone makers under the health-care law.

That’s been a concern for developers, who often operate with very narrow margins, said Rep. Marsha Blackburn (R-Tenn.), the committee’s vice chairman. Blackburn said she’s concerned that the possibility of these taxes could discourage developers from making health-related apps.

“We don’t want to see their research and development restricted” by new taxes, she said. “We’re hearing from our innovators that they’re concerned — not only with the what-ifs [such as] what are they going to begin to classify as a medical device, but also how intrusive is this going to be into the health care monitoring, disease maintenance and management.”

When asked for comment on the committee’s letter, FDA spokeswoman Synim Rivers confirmed the agency will respond to the letter, but declined further comment.

The market for health-related apps is already growing quickly. The market for mHealth app services will reach $26 billion by 2017, up from $718 million in 2011, according to a study from the consulting firm Research2Guidance.

In a best-case scenario, patients could use these apps to track valuable information, such as blood sugar levels or heart rates, which could help them work with their physicians to monitor their long-term health. But having apps collect all of that sensitive data also raises privacy concerns about how developers can use and repurpose that information.

The FDA has been mulling these issues for a couple of years, having been charged to devise a strategy that balances both innovation and privacy concerns.

In 2012, Congress gave the FDA the green light to define which medical apps would require its attention. The agency has asked for comment on a proposal that would give it regulation authority over accessories to existing medical devices, such as apps that show MRI scans, as well as apps and accessories that transform mobile devices into regulated medical devices, such as attachments or apps that turn smartphones into heart monitors. But the agency has yet to issue final guidance on the matter.

Blackburn said that lawmakers will be asking the FDA as well as the Department of Health and Human Services for clear guidance on the matter in the hearings next week.

On Tuesday, the committee’s subpanel on technology will speak with developers to look at how consumers are using existing health and fitness apps. The following day, the subcommittee on health will examine how health-care practitioners and patients use these kinds of apps for diagnoses. The series will wrap on Thursday, when the subcommittee on oversight and investigation hears testimony from the FDA and HHS officials.