The White House will put measures in place as soon as this summer to require further transparency from drug advertisers.

Any pharmaceutical company with a drug costing more than $35 for a one-month supply will be required to list the drug’s price — both list price and potential patient out-of-pocket cost — in television ads. This will function similarly to the regulations already in place requiring companies to list a drug’s potential side effects.

“Requiring the inclusion of drugs’ list prices in TV ads is the single most significant step any administration has taken toward a simple commitment: American patients deserve to know the prices of the healthcare they receive,” Health and Human Services Secretary Alex Azar said in a statement.

Johnson & Johnson beat the new laws to the punch with a February announcement, but other drugmakers have yet to announce their compliance. Many have previously protested the requirement, arguing that the numbers are misleading since customers rarely pay the full list price.

In a conference call with reporters Wednesday, Azar stressed the need for transparency from pharmaceutical companies, and lauded Johnson & Johnson’s early adoption of the practice.

Big announcement today: Drug companies have to come clean about their prices in TV ads. Historic transparency for American patients is here. If drug companies are ashamed of those prices—lower them! — Donald J. Trump (@realDonaldTrump) May 8, 2019

President Trump tweeted his own endorsement on Wednesday evening. “Drug companies have to come clean about their prices in TV ads,” he said. “Historic transparency for American patients is here. If drug companies are ashamed of those prices—lower them!”