A federal-court monitor of NYPD stop-and-frisk practices reported Tuesday that compliance with reforms is still incomplete, with 28 percent of the officers using new forms failing to fill in an adequate constitutional basis for a stop.

Monitor Peter Zimroth also reported that analysis of 600 reports using the new forms found that 27 percent didn’t report a legal basis for a frisk, 16 percent didn’t report a legal basis for a search, and that supervisors repeatedly approved the reports despite the deficiencies.

“It is apparent from focus group sessions and discussions with individual officers throughout the ranks that many police officers, including supervisors, are not well-informed as yet about the changes underway or the reasons for them and, therefore, have yet to internalize them,” Zimroth wrote “Many appear not to understand what is expected of them.”

“Ultimately, this is a challenge of leadership,” he said.

The report was the second Zimroth has filed with Manhattan U.S. District Judge Analisa Torres, who is overseeing the implementation of reforms following court filings that the NYPD engaged in unconstitutional stop and frisk practices that discriminated against minorities.

Consistent with NYPD statistics, the monitor confirmed that stops have been reduced dramatically, from 685,000 stops in 2011 to 45,787 in 2014 and 24,000 in 2015.

But, he noted, “The focus should not be on the number of stops per se, but rather on the lawfulness of the stops and whether the encounters are conducted in accordance with the Department’s principles of ‘courtesy, professionalism and respect.’”

The new forms limit checkboxes officers can use to justify a search and eliminate some overused catchall categories — such as “furtive movement” — while requiring more of a narrative, and review of the basis of the stop by supervisors.

They also have tear-off stubs to be given to people who were stopped but not arrested. Zimroth said in addition to substantial failures in articulating a sound basis for a stop, officers were frequently not giving out the receipts, and rarely filled out a stop form at all when an arrest wasn’t made.

The monitor called these “matters of concern” that “illustrate the gaps in knowledge among officers, reinforcing the importance of new in-service training on the revised stop and frisk policies and the new stop report form, and of the role of supervisors in evaluating the constitutionality of stops and frisks.”